U.S. patent application number 16/451695 was filed with the patent office on 2020-01-02 for device and method for setting display driver.
The applicant listed for this patent is SYNAPTICS INCORPORATED. Invention is credited to Kazutoshi AOGAKI, Hirobumi FURIHATA, Tomoo MINAKI.
Application Number | 20200005693 16/451695 |
Document ID | / |
Family ID | 69008291 |
Filed Date | 2020-01-02 |
United States Patent
Application |
20200005693 |
Kind Code |
A1 |
FURIHATA; Hirobumi ; et
al. |
January 2, 2020 |
DEVICE AND METHOD FOR SETTING DISPLAY DRIVER
Abstract
A system and method for generate mura correction data comprises
obtaining brightness values of a pixel-existing area and a
pixel-absent area of a display panel. Further, updated brightness
values are generated by replacing the brightness value of the
pixel-absent area with a suitable value. Mura correction data is
generated using the updated brightness values. A display driver is
configured with the mura correction data for updating a display
device.
Inventors: |
FURIHATA; Hirobumi; (Tokyo,
JP) ; AOGAKI; Kazutoshi; (Tokyo, JP) ; MINAKI;
Tomoo; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SYNAPTICS INCORPORATED |
San Jose |
CA |
US |
|
|
Family ID: |
69008291 |
Appl. No.: |
16/451695 |
Filed: |
June 25, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G09G 3/3225 20130101;
G09G 2320/0693 20130101; G09G 2320/0295 20130101; G09G 2320/0233
20130101; G09G 2320/0242 20130101; G09G 3/2092 20130101; G09G
2320/046 20130101; G09G 3/006 20130101 |
International
Class: |
G09G 3/00 20060101
G09G003/00; G09G 3/3225 20060101 G09G003/3225 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 29, 2018 |
JP |
2018-124094 |
Claims
1. A method, comprising: obtaining brightness values of a
pixel-existing area of a display panel and a pixel-absent area of
the display panel; generating updated brightness values by
replacing at least one of the brightness values of the pixel-absent
area with a suitable value; generating mura correction data based
on the updated brightness values; and configuring a display driver
with the mura correction data for updating the display panel.
2. The method according to claim 1, wherein obtaining the
brightness values comprises: capturing an image of the
pixel-existing area and the pixel-absent area while supplying drive
signals corresponding to a grayscale value to pixels of the
pixel-existing area; and obtaining the brightness values of the
pixel-existing area and the pixel-absent area from the captured
image, wherein replacing the brightness value with the suitable
value comprises determining the suitable value based on the
grayscale value.
3. The method according to claim 1, wherein the suitable value is
associated with a hypothetical pixel defined in the pixel-absent
area, and wherein replacing the brightness value with the suitable
value comprises determining the suitable value based on a position
of the hypothetical pixel in a vertical direction of the display
panel.
4. The method according to claim 1, wherein the suitable value is
associated with a hypothetical pixel defined in the pixel-absent
area, and wherein replacing the brightness value with the suitable
value comprises determining the suitable value based on a
brightness value of a pixel of the pixel-existing area, the pixel
being positioned in a horizontal direction with respect to the
hypothetical pixel.
5. The method according to claim 1, wherein the suitable value is
associated with a hypothetical pixel defined in the pixel-absent
area, and wherein replacing the brightness value with the suitable
value comprises determining the suitable value as a brightness
value of a pixel of the pixel-existing area, the pixel being
positioned in a horizontal direction with respect to the hypothetic
pixel within a predetermined distance from a boundary between the
pixel-existing area and the pixel-absent area.
6. The method according to claim 1, wherein the suitable value is
associated with a hypothetical pixel defined in the pixel-absent
area, and wherein replacing the brightness value with the suitable
value comprises calculating the suitable value through
interpolation between brightness values of a first pixel of the
pixel-existing area and a second pixel of the pixel-existing area,
the first pixel being positioned in a first direction parallel to a
horizontal direction with respect to the hypothetical pixel at a
boundary between the pixel-existing area and the pixel-absent area,
and the second pixel being positioned in a second direction
opposite to the first direction with respect to the hypothetical
pixel at a boundary between the pixel-existing area and the
pixel-absent area.
7. The method according to claim 1, further comprises: generating a
compressed mura correction data by compressing the mura correction
data; and writing the compressed mura correction data into the
display driver configured to drive the display panel.
8. The method according to claim 7, further comprising: generating
a decompressed mura correction data by decompressing the compressed
mura correction data; correcting an image data based on the
decompressed mura correction data; and driving a pixel of the
pixel-existing area based on the corrected image data.
9. A non-transitory tangible storage medium storing a program when
executed causes a processor to perform a method comprising:
obtaining brightness values of a pixel-existing area and a
pixel-absent area of a display panel; generate updated brightness
values by replacing at least one of the brightness values of the
pixel-absent area with a suitable value; generating mura correction
data based on the updated brightness values; and configuring a
display driver with the mura correction data for updating the
display panel.
10. The non-transitory tangible storage medium according to claim
9, wherein obtaining the brightness values comprises: displaying a
test image on the display panel based on a test image data; and
obtaining the brightness values of the pixel-existing area and the
pixel-absent area from a captured image of the display panel, the
captured image being captured while the test image is displayed on
the display panel, wherein replacing the brightness value of the
pixel-absent area with the suitable value comprises determining the
suitable value based on a grayscale value described in the test
image data.
11. The non-transitory tangible storage medium according to claim
9, wherein the suitable value is associated with a hypothetical
pixel defined in the pixel-absent area, and wherein replacing the
brightness value of the pixel-absent area with the suitable value
comprises determining the suitable value based on a position of the
hypothetical pixel in a vertical direction of the display
panel.
12. The non-transitory tangible storage medium according to claim
9, wherein the suitable value is associated with a hypothetical
pixel defined in the pixel-absent area, and wherein replacing the
brightness value with the suitable value comprises determining the
suitable value based on a brightness value of a pixel of the
pixel-existing area, the pixel being positioned in a horizontal
direction with respect to the hypothetical pixel.
13. The non-transitory tangible storage medium according to claim
9, wherein the suitable value is associated with a hypothetical
pixel defined in the pixel-absent area, and wherein replacing the
brightness value with the suitable value comprises determining the
suitable value as a brightness value of a pixel of the
pixel-existing area, the pixel being positioned in a horizontal
direction with respect to the hypothetic pixel within a
predetermined distance from a boundary between the pixel-existing
area and the pixel-absent area.
14. The non-transitory tangible storage medium according to claim
9, wherein the suitable value is associated with a hypothetical
pixel defined in the pixel-absent area, and wherein replacing the
brightness value with the suitable value comprises calculating the
suitable value through interpolation between brightness values of
first and second pixels of the pixel-existing area, the first pixel
being positioned in a first direction parallel to a horizontal
direction with respect to the hypothetical pixel at a boundary
between the pixel-existing area and the pixel-absent area, and the
second pixel being positioned in a second direction opposite to the
first direction with respect to the hypothetical pixel at a
boundary between the pixel-existing area and the pixel-absent
area.
15. The non-transitory tangible storage medium according to claim
9, wherein the method further comprises: generating a compressed
mura correction data by compressing the mura correction data; and
writing the compressed mura correction data into a display driver
configured to drive the display panel.
16. A display driver setting apparatus, comprising: a processor
configured to: obtain brightness values of a pixel-existing area
and a pixel-absent area of a display panel; generate updated
brightness values by replacing at least one of the brightness
values of the pixel-absent area with a suitable value; generate
mura correction data based on the updated brightness values; and
generate compressed mura correction data by compressing the mura
correction data; and an interface configured to supply the
compressed mura correction data to a display driver configured to
drive the display panel.
17. The display driver setting apparatus according to claim 16,
wherein the processor is further configured to: generate a test
image data corresponding to a test image; and obtain the brightness
values of the pixel-existing area and the pixel-absent area from a
captured image of the display panel, the captured image being
captured while the test image is displayed on the display panel,
and wherein the suitable value is determined based on a grayscale
value described in the test image data.
18. The display driver setting apparatus according to claim 16,
wherein the suitable value is associated with a hypothetical pixel
defined in the pixel-absent area, and wherein the suitable value is
determined based on a position of the hypothetical pixel in a
vertical direction of the display panel.
19. The display driver setting apparatus according to claim 16,
wherein the suitable value is associated with a hypothetical pixel
defined in the pixel-absent area, and wherein the suitable value is
determined based on a brightness value of a pixel of the
pixel-existing area, the pixel being positioned in a horizontal
direction with respect to the hypothetical pixel.
20. The display driver setting apparatus according to claim 16,
wherein the suitable value is associated with a hypothetical pixel
defined in the pixel-absent area, and wherein the suitable value is
determined as a brightness value of a pixel of the pixel-existing
area, the pixel being positioned in a horizontal direction with
respect to the hypothetic pixel within a predetermined distance
from a boundary between the pixel-existing area and the
pixel-absent area.
21. The display driver setting apparatus according to claim 16,
wherein the suitable value is associated with a hypothetical pixel
defined in the pixel-absent area, and wherein the suitable value is
calculated through interpolation between brightness values of first
and second pixels of the pixel-existing area, the first pixel being
positioned in a first direction parallel to a horizontal direction
with respect to the hypothetical pixel at a boundary between the
pixel-existing area and the pixel-absent area, and the second pixel
being positioned in a second direction opposite to the first
direction with respect to the hypothetical pixel at a boundary
between the pixel-existing area and the pixel-absent area.
22. A display driver, comprising: a non-volatile memory configured
to store compressed mura correction data; decompression circuitry
configured to generate decompressed mura correction data by
decompressing the compressed mura correction data; image processing
circuitry configured to correct an image data based on the
decompressed mura correction data; and driver circuitry configured
to drive a display panel based on the corrected image data.
23. The display driver according to claim 22, wherein the
compressed mura correction data is generated by compressing a mura
correction data generated based on a brightness value of a
pixel-existing area and a brightness value of a pixel-absent area,
the brightness value of the pixel-absent area being obtained by
replacing an initially-obtained brightness value of the
pixel-absent area with a suitable value.
24. The display driver according to claim 22, wherein the
compressed mura correction data comprises compressed data generated
based on a brightness value of a pixel-absent area of the display
panel, the brightness value of the pixel-absent area being obtained
by replacing an initially-obtained brightness value of the
pixel-absent area with a suitable value.
Description
CROSS REFERENCE
[0001] This application claims priority to Japanese Patent
Application No. 2018-124094, filed on Jun. 29, 2018, the disclosure
of which is incorporated herein by reference in its entirety.
BACKGROUND
Field
[0002] The present disclosure relates to a device and method for
setting a display driver.
Description of the Related Art
[0003] Display panels such as organic light emitting diode (OLED)
display panels and liquid crystal display (LCD) panels may
experience variations in pixel characteristics resulting from the
manufacturing process. Variations in the pixel characteristics may
cause mura in a displayed image. However, by performing mura
correction in a driver of a display panel or a display device, the
image quality of a displayed image may be improved.
SUMMARY
[0004] In one or more embodiments, a method comprises obtaining
brightness values of a pixel-existing area and a pixel-absent area
of a display panel. The method further comprises generating updated
brightness values by replacing at least one of the brightness
values of the pixel-absent area with a suitable value.
Additionally, the method comprises generating mura correction data
based on the updated brightness values. The method further
comprises configuring a display driver with the mura correction
data for updating the display panel.
[0005] In one embodiment, a non-transitory tangible storage medium
storing a program when executed causes a processor to perform a
method comprising obtaining brightness values of a pixel-existing
area and a pixel-absent area of a display panel. The method further
comprises generating updated brightness values by replacing at
least one of the brightness values of the pixel-absent area with a
suitable value. Additionally, the method comprises generating mura
correction data based on the updated brightness values. The method
further comprises configuring a display driver with the mura
correction data for updating the display panel.
[0006] In one or more embodiments, a display driver setting
apparatus comprises a processor and an interface. The processor is
configured to obtain brightness values of a pixel-existing area and
a pixel-absent area of a display panel. The processor is further
configured to generate updated brightness values by replacing at
least one of the brightness values of the pixel-absent area with a
suitable value. Additionally, the processor is configured to
generate mura correction data based on the updated brightness
values, and generate compressed mura correction data by compressing
the mura correction data. The interface is configured to supply the
compressed mura correction data to a display driver configured to
display the display panel.
[0007] In one embodiment, a display driver comprising a
non-volatile memory, decompression circuitry, image processing
circuitry, and driver circuitry. The non-volatile memory is
configured to store compressed mura correction data. The
decompression circuitry is configured to generate decompressed mura
correction data by decompressing the compressed mura correction
data. The image processing circuitry is configured to correct an
image data based on the decompressed mura correction data. The
driver circuitry is configured to drive a display panel based on
the corrected image data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] So that the manner in which the above recited features of
the present disclosure may be understood in detail, a more
particular description of the disclosure, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only some embodiments of this
disclosure and are therefore not to be considered limiting of its
scope, for the disclosure may admit to other equally effective
embodiments.
[0009] FIG. 1 is a block diagram illustrating one example
configuration of a display module, according to one or more
embodiments.
[0010] FIG. 2 schematically illustrates mura correction, according
to one or more embodiments.
[0011] FIG. 3 is a block diagram illustrating one example
configuration of a display driver setting apparatus, according to
one or more embodiments.
[0012] FIG. 4 schematically illustrates example contents of
brightness measurement data and mura correction data, according to
one or more embodiments.
[0013] FIG. 5 is a flowchart illustrating a method of setting a
display driver, according to one or more embodiments.
[0014] FIG. 6 schematically illustrates example contents of shape
data, brightness measurement data, and brightness measurement data
after a replacement process, according to one or more
embodiments.
[0015] FIG. 7 schematically illustrates brightness values described
in original brightness measurement data and those described in
brightness measurement data after the replacement process,
according to one or more embodiments.
[0016] FIG. 8 illustrates determination of a suitable value used in
the replacement process, according to one or more embodiments.
[0017] FIG. 9 illustrates calculation of a suitable value used in
the replacement process, according to one or more embodiments.
[0018] FIG. 10 schematically illustrates a distribution of
brightness values described in the brightness measurement data
after the replacement process, according to one or more
embodiments.
DETAILED DESCRIPTION
[0019] In one or more embodiments, as illustrated in FIG. 1, a
display module 100 comprises a display panel 1 and a display driver
2. In one or more embodiments, an OLED display panel may be used as
the display panel 1. In one or more embodiments, the display panel
1 comprises R pixels configured to display red, G pixels configured
to display green, and B pixels configured to display blue.
[0020] In one or more embodiments, a pixel-existing area 3, in
which the pixels are provided on the display panel 1, is not
rectangular. In one or more embodiments, pixel-absent areas 4, in
which no pixels exist, are provided at the corners of the display
panel 1, and thereby the corners of the pixel-existing area 3 are
rounded. Additionally, a pixel-absent area 5, in which no pixels
exist either, is provided along an upper edge of the display panel
1, and thereby a notch is formed in the pixel-existing area 3.
[0021] In one or more embodiments, the display driver 2 is
configured to receive an image data from a host 200 and drive the
respective pixels of the display panel 1 based on the received
image data. In one or more embodiments, the image data describes
grayscale values of the respective pixels of the display panel 1.
In one or more embodiments, the display driver 2 comprises an
interface 11, image processing circuitry 12, a non-volatile memory
13, decompression circuitry 14, and source driver circuitry 15.
[0022] In one or more embodiments, the interface 11 is configured
to receive various data from outside of the display driver 2 and
forward the same to desired circuitry. In one or more embodiments,
the interface 11 is configured to forward the image data received
from the host 200 to the image processing circuitry 12. In one or
more embodiments, the interface 11 is further configured to write
externally-received data into the non-volatile memory 13 in
accordance with the necessity.
[0023] In one or more embodiments, the image processing circuitry
12 is configured to perform desired image processing on the image
data received from the host 200. In one or more embodiments, the
image processing performed in the image processing circuitry 12
comprises mura correction (or demura processing). In one or more
embodiments, mura correction for an image data associated with a
target pixel involves correcting the image data based on a mura
correction data generated based on the characteristics of the
target pixel. Referring to FIG. 2, when the target pixel is
manufactured to exhibit a reduced brightness level in the
manufacturing process, in one or more embodiments, the mura
correction data associated with the target pixel is generated to
perform mura correction to increase the brightness level of the
target pixel. When the target pixel is manufactured to exhibit an
increased brightness level in the manufacturing process, in one or
more embodiments, the mura correction data associated with the
target pixel is generated to perform mura correction to decrease
the brightness level of the target pixel. Such mura correction
effectively cancels the variations in the pixel characteristics,
suppressing mura in the displayed image.
[0024] Referring back to FIG. 1, the non-volatile memory 13 is
configured to store mura correction data used for the mura
correction performed in the image processing circuitry 12, in one
or more embodiments. In one or more embodiments, compressed mura
correction data 20 obtained by compressing the mura correction data
is stored in the non-volatile memory 13, not in the original form
of the mura correction data.
[0025] The decompression circuitry 14 is configured to generate
decompressed mura correction data by decompressing the compressed
mura correction data 20 read out from the non-volatile memory 13
and supply the decompressed mura correction data to the image
processing circuitry 12. The decompressed mura correction data is
used in the mura correction in the image processing circuitry
12.
[0026] In one or more embodiments, the source driver circuitry 15
is configured to receive an image data generated by the image
processing in the image processing circuitry 12 and drive the
respective pixels of the display panel 1 based on the received
image data.
[0027] In one or more embodiments, the display driver 2 is
configured to output drive signals to the display panel 1 in such a
matter that an image is displayed in a rectangular area
encompassing the pixel-existing area 3 of the display panel 1, for
example, a rectangular area circumscribing the pixel-existing area
3, although the pixel-existing area 3 is not actually rectangular.
In one or more embodiments, the display driver 2 is configured to
output the drive signals under an assumption that pixels are
hypothetically defined also in the pixel-absent areas 4 and 5,
although no pixels actually exist in the pixel-absent areas 4 and
5. This may simplify the configuration of the display driver 2.
Since no pixels actually exist in the pixel-absent areas 4 and 5,
this operation eventually displays an image only in the
pixel-existing area 3.
[0028] Pixels hypothetically defined in the pixel-absent areas 4
and 5 may be hereinafter referred to as hypothetical pixels.
Similarly, R, G, and B pixels hypothetically defined in the
pixel-absent areas 4 and 5 may be hereinafter referred to as
hypothetical R, G, and B pixels, respectively.
[0029] In one or more embodiments, the image data supplied to the
display driver 2 from the host 200 comprises image data associated
with the hypothetical pixels of the pixel-absent areas 4 and 5 in
addition to those associated with the pixels of the pixel-existing
area 3. In view of this, in one or more embodiments, the image
processing circuitry 12 is configured to perform mura correction on
the image data associated with the hypothetical pixels of the
pixel-absent areas 4 and 5 in addition to those associated with the
pixels of the pixel-existing area 3.
[0030] Referring to FIG. 3, in one or more embodiments, the
compressed mura correction data 20 are supplied to the display
driver 2 and stored in the non-volatile memory 13 in a testing
process of the display module 100. In one or more embodiments, the
compressed mura correction data 20 are generated by the display
driver setting apparatus 300 in the testing process. The generated
compressed mura correction data 20 are supplied to the interface 11
of the display driver 2 and then transferred to the non-volatile
memory 13.
[0031] The display driver setting apparatus 300 is configured to
obtain brightness values of the pixel-existing area 3 and the
pixel-absent areas 4 and 5 of the display panel 1 in the testing
process of the display module 100. In one or more embodiments, the
display driver setting apparatus 300 comprises an imaging device 21
and a setting computer 22. The imaging device 21 is configured to
capture an image of the display panel 1. In one or more
embodiments, a coverage area for which the image is captured on the
display panel 1 is rectangular, and the coverage area incorporates
the pixel-absent areas 4 and 5 in addition to the pixel-existing
area 3. In one or more embodiments, the setting computer 22 is
configured to obtain brightness measurement data describing
brightness values of the respective pixels and the respective
hypothetical pixels from the image captured by the imaging device
21. In one or more embodiments, the setting computer 22 is further
configured generate mura correction data from the brightness
measurement data and generate the compressed mura correction data
20 by compressing the mura correction data thus generated.
[0032] In one or more embodiments, the setting computer 22 is
configured to generate the mura correction data and the compressed
mura correction data 20 through software processing. In one or more
embodiments, the setting computer 22 comprises an interface 23, a
storage device 24, a processor 25, and an interface 26.
[0033] In one or more embodiments, the interface 23 is configured
to receive the brightness measurement data from the imaging device
21 and supply to the imaging device 21 control data for controlling
the imaging device 21.
[0034] In one or more embodiments, the storage device 24 is
configured to store various data used for generating the mura
correction data and the compressed mura correction data 20. In one
or more embodiments, mura correction data calculation software 30
is installed on the storage device 24; the storage device 24 is
used as a non-transitory tangible storage medium storing the mura
correction data calculation software 30. The mura correction data
calculation software 30 may be offered in the form of a computer
program product recorded in a computer-readable recording medium
27, or in the form of a computer program product downloadable from
a server.
[0035] In one or more embodiments, the processor 25 is configured
to execute the mura correction data calculation software 30 to
achieve various data processing operations for the generation of
the mura correction data and the compressed mura correction data
20. In one or more embodiments, the processor 25 is further
configured to generate a test image data corresponding to a test
image to be displayed on the display panel 1 when the brightness
values of the pixel-existing area 3 and the pixel-absent areas 4, 5
are obtained in the testing process and supply the generated test
image data to the display driver 2. In one or more embodiments, the
processor 25 is further configured to generate the control data to
control the imaging device 21 and supply the same to the imaging
device 21. In one or more embodiments, the imaging device 21 is
configured to capture an image under the control of the control
data. In one or more embodiments, the processor 25 is further
configured to generate the brightness measurement data from the
image captured by the imaging device 21 and generate the mura
correction data from the brightness measurement data. In one or
more embodiments, the processor 25 is further configured to
generate the compressed mura correction data 20 by compressing the
mura correction data thus generated.
[0036] In one or more embodiments, the interface 26 is configured
to supply to the display driver 2 the test image data and the
compressed mura correction data 20 generated by the processor
25.
[0037] In one or more embodiments, the mura correction data
generated by the display driver setting apparatus 300 comprise
those used for mura correction of the image data associated with
the hypothetical pixels of the pixel-absent areas 4 and 5 in
addition to those used for mura correction of the image data
associated with the pixels of the pixel-existing area 3. In one or
more embodiments, the coverage area for which the imaging device 21
captures an image on the display panel 1 is rectangular; and the
imaging device 21 is configured to capture the image of the display
panel 1 so that the coverage area incorporates the pixel-absent
areas 4 and 5 of the display panel 1 in addition to the
pixel-existing area 3. In one or more embodiments, the processor 25
is configured to generate the brightness measurement data, which
describe the brightness values of the pixels of the pixel-existing
area 3 and those of the hypothetical pixels of the pixel-absent
areas 4 and 5, from the image thus captured. In one or more
embodiments, the brightness measurement data describe brightness
values at positions where the pixels are located in the
pixel-existing area 3 and further describe brightness values at
positions where the hypothetical pixels are defined in the
pixel-absent areas 4 and 5. In one or more embodiments, the
processor 25 is further configured to generate the mura correction
data associated with the hypothetical pixels of the pixel-absent
areas 4 and 5 in addition to the mura correction data associated
with the pixels of the pixel-existing area 3, based on the
generated brightness measurement data.
[0038] In one or more embodiments, to reduce the hardware size for
storing the compressed mura correction data 20 in the display
driver 2, the mura correction data is generated so that the
compression ratio in the generation of the compressed mura
correction data 20 is increased. Referring to FIG. 4, since no
pixels actually exist in the pixel-absent areas 4 and 5, brightness
measurement data which describes brightness values of zero or those
close to zero may be obtained from the captured image for
respective positions in the pixel-absent areas 4 and 5, while
brightness measurement data which describes brightness values apart
from zero may be obtained for respective positions in the
pixel-existing area 3. To improve the compression ratio of the mura
correction data, in one or more embodiments, brightness measurement
data obtained by a replacement process is used to generate the mura
correction data in place of the original brightness measurement
data obtained from the captured image. In one or more embodiments,
the replacement process involves replacing the brightness value of
at least one hypothetical pixel of the pixel-absent areas 4 and 5
in the original brightness measurement data with a "suitable"
value. This replacement process may reduce variations in the
brightness values at the boundaries between the pixel-existing area
3 and the pixel-absent areas 4 and 5 and thereby reduce variations
in the mura correction data. This may improve the compression ratio
of the mura correction data. A detailed description will be given
later of a method of determining the "suitable" value for reducing
the variations in the mura correction data. The replacement process
may also contribute improvement in the image quality, because the
replacement process reduces compression distortion of the mura
correction data through reduction in the variations in the mura
correction data. In the following, a detailed description is given
of the generation of the mura correction data and the setting of
the compressed mura correction data 20 to the display driver 2,
according to one or more embodiments.
[0039] As illustrated in FIG. 5, in one or more embodiments, shape
data representing the shape of the pixel-existing area 3 are
respectively obtained for the R pixels, the G pixels, and the B
pixels in step S01. Various pixel structures may be used for the
display panel 1, and therefore the shape of the pixel-existing area
3 may be different among the R pixels, the G pixels, and the B
pixels, especially when an OLED display panel is used as the
display panel 1. In view of this, the shape data is respectively
obtained for the R pixels, the G pixels, and the B pixels, in one
or more embodiments. In the following, the shape data representing
the shape of the pixel-existing area 3 for the R pixels may be
referred to as R shape data. Similarly, the shape data representing
the shape of the pixel-existing area 3 for the G pixels may be
referred to as G shape data, and the shape data representing the
shape of the pixel-existing area 3 for the B pixels may be referred
to as B shape data.
[0040] In one or more embodiments, the R shape data is obtained as
follows. Referring to FIG. 6, a test image data which drives all
the R pixels of the display panel 1 to be of the highest brightness
level and drives all the G and B pixels to be of the lowest
brightness level is supplied to the display driver 2 from the
setting computer 22 of the display driver setting apparatus 300 in
one or more embodiments. In one or more embodiments, the test image
data specifies the grayscale values of all the R pixels as the
highest grayscale value, for example, "255" and specifies the
grayscale values of all the G and B pixels as the lowest grayscale
value, for example, "0." This results in supplying drive signals
corresponding to the highest grayscale value to the R pixels to
drive the R pixels to be of the highest brightness level and
supplying drive signals corresponding to the lowest grayscale value
to the G and B pixels to drive the G and B pixels to be of the
lowest brightness level, in one or more embodiments. In one or more
embodiments, an image is captured by the imaging device 21 in the
state in which all the R pixels of the display panel 1 are driven
to be of the highest brightness level and all the G and B pixels
are driven to be of the lowest brightness level. In one or more
embodiments, a brightness measurement data is generated based on
the image thus captured, and the R shape data, which represents the
shape of the pixel-existing area 3 for the R pixels, is generated
based on the brightness measurement data thus generated. In one or
more embodiments, the R shape data is generated so that the R shape
data defines the pixel-existing area 3 as an area in which pixels
of the highest brightness level or brightness levels higher than a
predetermined brightness level close to the highest brightness
level are arranged and defines the pixel-absent areas 4 and 5 as an
area in which pixels of a brightness level of zero or brightness
levels lower than a predetermined brightness level close to zero
are arranged.
[0041] In one or more embodiments, G and B shape data is obtained
in a similar way. When the G shape data is obtained, in one or more
embodiments, an image is captured by the imaging device 21 in the
state in which all the G pixels of the display panel 1 are driven
to be of the highest brightness level and all the B and R pixels
are driven to be of the lowest brightness level. A brightness
measurement data is generated based on the image thus captured, and
the G shape data is generated based on the brightness measurement
data thus generated. Similarly, when the B shape data is obtained,
in one or more embodiments, an image is captured by the imaging
device 21 in the state in which all the B pixels of the display
panel 1 are driven to be of the highest brightness level and all
the R and G pixels are driven to be of the lowest brightness level.
A brightness measurement data is generated based on the image thus
captured, and the B shape data is generated based on the brightness
measurement data thus generated.
[0042] Referring back to FIG. 5, in step S02 following step S01,
brightness measurement data is obtained while the R, G, and B
pixels are individually driven with specified grayscale values, in
one or more embodiments. In one or more embodiments, a brightness
measurement data for the R pixels is obtained in a state in which
drive signals corresponding to a specified grayscale value are
supplied to the R pixels and drive signals corresponding to the
lowest brightness level, that is, the lowest grayscale value are
supplied to the G and B pixels. The brightness measurement data
thus obtained may be hereinafter referred to as R brightness
measurement data. In one or more embodiments, a brightness
measurement data for the G pixels is obtained in a state in which
drive signals corresponding to a specified grayscale value are
supplied to the G pixels and drive signals corresponding to the
lowest brightness level, that is, the lowest grayscale value are
supplied to the B and R pixels. The brightness measurement data
thus obtained may be hereinafter referred to as G brightness
measurement data. In one or more embodiments, a brightness
measurement data for the B pixels is obtained in a state in which
drive signals corresponding to a specified grayscale value are
supplied to the B pixels and drive signals corresponding to the
lowest brightness level, that is, the lowest grayscale value are
supplied to the R and G pixels. The brightness measurement data
thus obtained may be hereinafter referred to as B brightness
measurement data.
[0043] In one or more embodiments, the R brightness measurement
data, the G brightness measurement data, and the B brightness
measurement data is obtained for a plurality of grayscale values.
An R brightness measurement data for a certain grayscale value is
obtained in a state in which drive signals corresponding to the
grayscale value are supplied to the R pixels and drive signals
corresponding to the lowest brightness level, that is, the lowest
grayscale value are supplied to the G and B pixels. The similar
goes for the G brightness measurement data, and the B brightness
measurement data. When a brightness measurement data is obtained in
step S01 in the state in which drive signals corresponding to the
highest grayscale value are supplied to all the R pixels and drive
signals corresponding to the lowest grayscale value are supplied to
all the G and B pixels, the brightness measurement data thus
obtained may be used as the R brightness measurement data
corresponding to the highest grayscale value. The similar goes for
the G brightness measurement data and the B brightness measurement
data.
[0044] In one or more embodiments, in step S03 following step S02,
a replacement process is performed to replace the brightness values
of the hypothetical pixels of the pixel-absent areas 4 and 5 with a
predetermined "suitable value" for each of the R brightness
measurement data, the G brightness measurement data, and the B
brightness measurement data corresponding to each grayscale value.
Referring to FIG. 6, the shape data obtained in step S01 are used
in this replacement process, in one or more embodiments. In one or
more embodiments, in the replacement process for the R brightness
measurement data, the brightness values of the hypothetical R
pixels of the pixel-absent areas 4 and 5 are identified based on
the R shape data, and the brightness values of the hypothetical R
pixels are replaced with a "suitable value." In one or more
embodiments, in the replacement process for the G brightness
measurement data, the brightness values of the hypothetical G
pixels of the pixel-absent areas 4 and 5 are identified based on
the G shape data, and the brightness values of the hypothetical G
pixels are replaced with a "suitable value." In one or more
embodiments, in the replacement process for the B brightness
measurement data, the brightness values of the hypothetical B
pixels of the pixel-absent areas 4 and 5 are identified based on
the B shape data, and the brightness values of the hypothetical B
pixels are replaced with a "suitable value." In one or more
embodiments, the shape data obtained in step S01 are used for all
the specified grayscale values in the replacement process in step
S03. The use of the shape data, which are obtained in the state in
which the pixels are driven to be of the highest brightness level,
makes it possible to accurately identify the brightness values of
the pixel-absent areas 4 and 5.
[0045] In one or more embodiments, the "suitable value" may be
determined based on the grayscale value described in the test image
data. The suitable value used in the replacement process for an R
brightness measurement data corresponding to a certain grayscale
value may be determined based on the grayscale value of the R
pixels described in the test image data used for obtaining the
captured image used for generating the R brightness measurement
data. In one or more embodiments, the similar applies to the
suitable values used in the replacement processes for the G
brightness measurement data and the B brightness measurement
data.
[0046] In one or more embodiments, the "suitable value"
corresponding to a certain grayscale value may be determined as a
brightness value expected for pixels hypothetically existing in the
pixel-absent areas 4 and 5 when the hypothetically-existing pixels
are supplied with drive signals corresponding to the grayscale
value. For example, when the grayscale value of the R pixels are
described as a value from "0" to "255" in the test image data
supplied to the display driver 2 in obtaining the R brightness
measurement data and the brightness values of the R pixels are
described as values from "0" to "255" in the R brightness
measurement data, the "suitable value" may be determined as being
identical to the grayscale value of the R pixels described in the
test image data. In one or more embodiments, the similar applies to
the G brightness measurement data and the B brightness measurement
data.
[0047] Referring back to FIG. 5, in step S04 following step S03,
mura correction data is generated based on the R, G, and B
brightness measurement data obtained by the replacement process in
step S03, in one or more embodiments. In one or more embodiments,
the mura correction data associated with the R pixels are generated
from the R brightness measurement data. In one or more embodiments,
the mura correction data associated with the G pixels are generated
from the G brightness measurement data, and the mura correction
data associated with the B pixels are generated from the B
brightness measurement data.
[0048] In step S05, the compressed mura correction data 20 are
generated by compressing the mura correction data, in one or more
embodiments.
[0049] In step S06, the compressed mura correction data 20 are
transferred to the display driver 2 from the display driver setting
apparatus 300 and written into the non-volatile memory 13 of the
display driver 2, in one or more embodiments. This completes
setting the compressed mura correction data 20 to the display
driver 2, in one or more embodiments.
[0050] As thus described, in one or more embodiments, variations in
the mura correction data is reduced to improve the compression
ratio of the mura correction data through the replacement process
which replaces the brightness values of the hypothetical pixels of
the pixel-absent areas 4 and 5 with a suitable value. This may
effectively reduce the size of the compressed mura correction data
20, making it possible to reduce the capacity of the non-volatile
memory 13. Such replacement process may also improve the image
quality, since the reduction in the variations in the mura
correction data reduces the compression distortion of the mura
correction data.
[0051] In one or more embodiments, a common shape data may be
obtained for the R pixels, the G pixels, and the B pixels in step
S01, when the shape of the pixel-existing area 3 can be considered
as the same for the R pixels, the G pixels, and the B pixels. In
this case, in one or more embodiments, an image is captured in a
state in which all the pixels of the display panel 1 are driven to
be of the highest brightness level, a brightness measurement data
describing the brightness values of the respective pixels is
generated from the captured image, and a common shape data is
generated from the brightness measurement data thus generated. In
such an embodiment, the common shape data is used to identify the
brightness values of the hypothetical pixels of the pixel-absent
areas 4 and 5 for all the R, G, and B brightness measurement data
in the replacement process in step S03.
[0052] The "suitable value" used in the replacement process in step
S03 may be determined based on the position of the corresponding
hypothetical pixel in the vertical direction in the display panel
1; the vertical direction referred herein is the direction in which
the source lines are extended in the display panel 1, indicated as
the Y axis direction of the XY Cartesian coordinate system in FIG.
7. The brightness values of the pixels of the display panel 1 may
depend on the positions of the pixels in the vertical direction,
depending on the resistances of the source lines and the drive
capability of the source driver circuitry 15. In such a case, the
compression ratio of the mura correction data may be improved by
determining the "suitable value" based on the position of the
corresponding hypothetical pixel in the vertical direction of the
display panel 1. In one or more embodiments, when an OLED display
panel is used as the display panel 1, a suitable value representing
a reduced brightness level is used in a replacement process for a
hypothetical pixel positioned away from the display driver 2, and a
suitable value representing an increased brightness level is used
in a replacement process for a hypothetical pixel positioned close
to the display driver 2.
[0053] In one or more embodiments, the "suitable value" used in the
replacement process for a hypothetical pixel is calculated based on
the brightness value of a pixel of the pixel-existing area 3
positioned in the horizontal direction with respect to the
hypothetical pixel, to determine the "suitable value" used in the
replacement process depending on the position of the hypothetical
pixel. The "horizontal direction" referred herein is the direction
orthogonal to the above-described vertical direction, indicated as
the X axis direction of the XY Cartesian coordinate system in FIG.
7. In one or more embodiments, a "suitable value" is individually
calculated for each of the hypothetical R pixels, the hypothetical
G pixels, and the hypothetical B pixels.
[0054] In one or more embodiments, a brightness value of a pixel of
the pixel-existing area 3 positioned in the horizontal direction
with respect to a hypothetical pixel may be copied as the "suitable
value" used in the replacement process for the hypothetical pixel.
As illustrated in FIG. 8, for example, in the replacement process
for a hypothetical R pixel 31 defined in a pixel-absent area 4, the
suitable value for the hypothetical R pixel 31 may be determined as
the brightness value of an R pixel 32 positioned in the horizontal
direction with respect to the hypothetical R pixel 31 within a
predetermined distance from the boundary between the pixel-existing
area 3 and the pixel-absent area 4. In one or more embodiments, the
suitable value may be determined as the brightness value of the R
pixel 32 closest to the boundary between the pixel-existing area 3
and the pixel-absent area 4. In one or more embodiments, the
suitable value may be determined as the brightness value of an R
pixel 32 positioned within a predetermined distance from the
boundary between the pixel-existing area 3 and the pixel-absent
area 4 other than the R pixel 32 closest to the boundary; for
example, the suitable value may be determined as the brightness
value of an R pixel 32 adjacent to the R pixel 32 closest to the
boundary. The replacement process may be performed similarly for
the hypothetical G pixels and the hypothetical B pixels.
[0055] When a hypothetical pixel is defined at a position
sandwiched by the pixel-existing area 3 in the horizontal
direction, the suitable value used in the replacement process for
the hypothetical pixel may be calculated through interpolation. For
example, as illustrated in FIG. 9, the suitable value used in the
replacement process for a hypothetical R pixel 33 defined in the
pixel-absent area 5 may be calculated through interpolation between
the brightness value of an R pixel 34 positioned in the -X
direction with respect to the hypothetical R pixel 33 at the
boundary between the pixel-existing area 3 and the pixel-absent
area 5 and that of an R pixel 35 positioned in the +X direction
with respect to the hypothetical R pixel 33 at the boundary between
the pixel-existing area 3 and the pixel-absent area 5. In one or
more embodiments, the suitable value used in the replacement
process for the hypothetical R pixel 33 may be calculated through
interpolation between the brightness values of the R pixels 34 and
35 depending on the distance d.sub.1 between the hypothetical R
pixel 33 and the R pixel 34 and the distance d.sub.2 between the
hypothetical R pixel 33 and the R pixel 35. In this case, the
suitable values used in the replacement processes for the
hypothetical G pixels and the hypothetical B pixels may be
similarly calculated.
[0056] Determining or calculating the "suitable values" as
described above may make it possible to reduce the variations in
the brightness measurement data at the boundaries between the
pixel-existing area 3 and the pixel-absent areas 4 and 5 after the
replacement process as illustrated in FIG. 10, effectively
improving the compression ratio of the mura correction data.
[0057] Although various embodiments of this disclosure have been
specifically described in the above, the technologies presented in
this disclosure may be implemented with various modifications. For
example, the display panel 1 may additionally comprise pixels
displaying a different color from red, green and blue, for example,
pixels displaying yellow or while. In this case, a shape data and
brightness measurement data may be obtained for the different color
and a similar process to those for the R, G, and B pixels may be
performed.
* * * * *